public class Example4_7 {
   public static void main (String args[]) {
     Battery nanfu=new Battery(100);
     System.out.println("南孚电池的储电量是:"+nanfu.electricityAmount);
     Radio radio = new Radio ();
     System.out.println("收音机开始使用南孚电池");
     radio.openRadio(nanfu);
     System.out.println("目前南孚电池的储电量是:"+nanfu.electricityAmount);
   }
}

